The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Different types of interconnected computing devices such as switches, routers, servers and/or data storage devices are typically located in computer rooms or server rooms that may be a part of a datacenter, an on-premises computer system or other computing environment. Data centers may be used to provide remote, on-demand data storage, computing and/or software services to governmental entities, enterprises and/or consumers. The data centers rent resources such as physical machines, software, storage or other computing resources and allow the rented capacity to be automatically increased or decreased as demand changes.
The computing devices in the computer or server room of the datacenter are interconnected using data carrying cables such as Ethernet cables. Digital data is transmitted between the computing devices at very high data transmission rates. The computing devices are generally packed closely together. For example, the servers and switches may be arranged adjacent to one another on racks.
The computing devices generate a significant amount of heat during operation. Cooling airflow may be provided to cool the computing devices. In some installations, tight packing makes it difficult to cool the computing devices. Data attenuation can be affected by a number of factors including operating temperature, the length of the connecting cables and the gauge of the conductors that are used in the cables.
Ethernet cables may be used to physically connect ports of the switches to the servers. The cables are typically connected to ports of the server, bent (e.g. approximately 90°) and travel along a side of the rack. The cables are usually bent again (e.g. approximately 90°) and are connected to another device such as a switch or router. This physical layout allows the servers to be removed from the racks without being obstructed by the cables. However, this physical layout also tends to increase cable length, which increases insertion loss.
Cables using thinner gauge conductors can be used for improved bending flexibility and manageability. Cables using thinner gauge conductors are also easier to connect to small form factor connectors and tend to block less cooling air flow. As the cable length is increased, however, the insertion loss also increases due to increased effective resistance of the thinner gauge conductor. At high frequencies, current travels along an outer surface of the conductor due to field strength (inductance) (referred to as skin effect). Larger gauge cables have higher surface area than smaller gauge cables. Therefore, data carrying cables with thicker-gauge conductors are often used in applications requiring longer spans and higher data rates. For example, high speed Ethernet signaling (such as 50 Gb/s non-return to zero (NRZ) modulation) generally requires low insertion loss and therefore thicker gauge conductors are used.